Hypsizygus marmoreus

I. Introduction

Hypsizygus marmoreus is also called Zhengjigu, jade mushroom (Yuxun), spot jade mushroom (Banyuxun) in China, belonging to Hypsizygus, Tricholomataceae, Agaricales, hymenomycetidae, Basidiomycetes. Its taste is more fresh than that of Pleurotus ostreatus, context is more thick than that of Pholiota nameko, character is more pliable than that of Lentinula edodes, and it even has unique fragrance of crab, so its mouth feel is good. This mushroom contains complete kinds of amino acids, including the 8 kinds of necessary amino acid of human body, and several kinds of polysaccharide. Its extracts drawn by hot water or organic solvent from the fruit body have the role that clears away the free radical of human body, which suggests that the mushroom have the effects of preventing and curing cancer, raising immunity, defending senescence and prolong life.

II Biological characteristics

1. Configuration of Hypsizygus marmoreus

The fruit body cluster, each cluster include 15-50 individual plant. Sometimes it grows individually, with fewer number and bigger cap. The cap looks like a hemisphere when it is young, with its edge involuting and then gradually flatting. The cap is near white to gray-brown with diameter of 4-15 cm and dark marble stripe on it. Its gill is near white, serried to slightly sparse. The stipe has a length of 3-10 cm and diameter of 0.3-0.6 cm, from the center of side of the cap. The spore has a shape of broad egg or near round, translucent under microscope and white when piling up.

2. Biological character

Hypsizygus marmoreus is a kind of edible mushroom occurring in autumn and winter of the north temperature zone.

(1) Characteristics of the culture

It has white mycelia of plumule shape, no thick aerial hypha, no yellow liquid exudation and no coat. It may produce arthrospore and chlamydospore during the culture. Hypsizygus marmoreus has a relative stronger resistance to bad environment. Its growth condition has a lot of sameness in compare with that of Lentinus edodes and Pleurotus ostreatus, but also some difference. Furthermore, the different strains of this mushroom don’t have the same requirement to the growth conditions, which is not clear. The main growth requirement is introduced as below.

Nutrition: It is a wood rotting fungus of low temperature type. The cultivation materials can be got in many ways. The main raw materials can be sawdust, corn core, sugarcane residue and cottonseed shell, among them cottonseed shell produce the highest output. Adding little supplementary materials such as rice bran, wheat bran, soybean bran, cottonseed cake and corn flour in cultivation can raise the yield.

Temperature: Changing temperature is needed in the fruiting of this mushroom, just as that of Flammulina velutipes, Pholiota nameko, Lentinula edodes and Pleurotus ostreatus. The temperature range is 9-30°C for mycelia growth, and the optimum temperature is 22-24°C. The premordium differentiation require 4-18°C, and the optimum is 10-14°C.

Moisture: The moisture of the substrate should be adjusted to about 65%. The culture substrate will gradually dry for the long spawn-running period, so it is necessary to supplement water to make the moisture reach 70-75% before fruiting. In the button differentiation phase, the relative humidity in mushroom house should be 98-100%. When the fruit body is developing, the value should be 90-95%.

Light: No light is needed for mycelia growth, but weak light excitement is needed for the button differentiation. The fruit body has phototropism when growing, so fluorescent lamp should be opened for 10-15 hr if the mushroom is cultivated in basement or cavern.

Air: Fresh air is necessary for every phase of its cultivation. The substrate should be the mixture of different size particles, and avoid over wet. The CO2 concentration in mushroom house should be properly controlled. When lots of premordium appear ventilation should be performed 4-8 times per hour.

PH value: The optimum pH value during mycelia growing is 6.5-7.5. The spawn running period need 30-45 days, totally 30-60 days may be needed for mycelia maturation with ability of fruiting. 7-12 days is required for button differentiation, while it is 5-7 days for fruit body development. Control the time properly based on different strains and temperature. Careful observation and prompt control is the key point of mushroom production and quality.

III. Cultivation technology

1. Cultivation mode:

Similar as that of Pleurotus ostreatus, so bottle or bag cultivation can be adopted.

2. Cultivation season

Because of its relative long growth period, generally the inoculation time can be from early September to May of next year, based on the local climate and temperature controlling ability of mushroom house. If air conditioning is used, cultivation will be arranged according to the market.

Commonly, period from early September to mid of May of next year can be inoculation time. If the time is relative late, via cross-summer management the mushroom can be harvested from early of October to mid of November.

3. Cultivation yard

The cultivation yard of this mushroom can be plastic mushroom shed, vacant room, basement and air raid shelter and so on. If permitted, special mushroom house can be used in the cultivation.

4. Spawn

The spawn preparation is similar to that of Agaricus bisporus and Pleurotus ostreatus, and has three steps of stock spawn, pre-culture spawn and cultivation spawn.

5. Formula of the substrate

Several materials can be the cultivation substrate of Hypsizygus marmoreus, but the most suitable materials with highest production is cottonseed shell. The following is some prescriptions introduced as reference.

Preparation: Take the prescription (1.) as example, in the afternoon one-day before bag filling, weigh up the solarized cottonseed shell and supplementary material according to the proportion, and mix well. Dissolve the 3% lime with water, collect the supernatant, and add to proper water. Then add the limewater into the materials when turning it. When finished, pile up and cover the materials with plastic film. Lay open the compost the next day, add rice bran, gypsum and mix, determine the moisture by holding hand (2-3 drops water exude from the finger gap), measure the pH value with extensive test paper till the optimum.

6. Bag (bottle) cultivation

In the cultivation of Hypsizygus marmoreus, plastic bag is used more popularly than bottle. The flow of the technology is:

substrate preparation

bag (bottle) filling

ferruling and sealing

sterilization

inoculation

spawn running

premordium inducement

fruiting.

(1) Substrate preparation:

Cultivation substrate should be prepared based on the local materials resource and substrate formula reference.

(2) Bag (bottle) filling:

The mycelia bag needs a long time for spawn running and fruiting. Normally the polypropylene bag with size of 30 cm × 15 cm × 0.05 cm or the low pressure polyethylene bag of 17 cm × 33 cm × 0.05cm is utilized. Be careful when filling the bags to avoid dilapidation. Manual work and machine can be adopted in filling bags. If permitted, the machine filling 400 bags per hour for 5 persons is suitable.

(3) Ferruling and sealing:

When bags filling finish, add the ferrule in time, close the bag mouth with packing string.

(4) Sterilization:

Autoclaving should last 2 hours under 1.5 Kg/cm2, and it should last 10 hours under normal pressure.

(5) Inoculation:

Because of its long spawn running time, strict sterile operation should be performed in inoculation. The stock spawn in 750 mL bottle can be transferred to 30 bags with size of 17 cm × 35 cm × 0.05 cm.

(6) Spawn running:

After inoculation, the mycelia bags should be removed into running room in time, and keep the room temperature of 18-26°C. The bags will be full of mycelia 40 days later. After further 30 days, the mycelia will excrete buff matter, suggesting its physiological maturation.

(7) Fruiting management:

Remove the matured mycelia bags to fruiting room. They can be arrayed in many ways, such as up righting on the bed and piling up flatly on the each side of the ground channel. Then carry out the following operation step by step.

Mycelia scratching: Open the bags; get rid of the old mycelia around in order to promote the premordium-forming cluster from where inoculated. Through the treatment, the small fruit bodies will grow around and result in good quality mushroom with fat stipe, complete cap and thick context. After mycelia scratching, immit clean water onto the substrate, and pour away the non absorbed water 2-3 hours later.

Button promotion: Cover wet newspaper or coarse calico on the bags, drop the temperature to 13-15°C at the same time, enhance the ventilation, so as to promote the button forming. In general, the gray-brown button with pinhead shape can be seen on the substrate surface 10-15 days later.

Mushroom development: When buttons appear, take off the covering and keep the room temperature of about 14°C. Sprinkle water to the air and ground to keep the humidity of 90%, avoid sprinkling water to the button directly. Reinforce the ventilation to keep the air fresh, supply the light of about 500 Lux, and the mushroom can be harvested 5-7 days later.

(8) High production cultivation technology by the application of solid water storing method

Arraying mycelia bags: Open one side of the matured mycelia bag, role up the plastic bag to the other side but don’t take off it, which will become the insulation of soil and fruit body and avoid the soil leave on the fruit body when fruiting. On the midst of the ground channel, arrange the mycelia bags in two lines with head to head at a distance of 8cm, the plastic head outside. Remained 2cm gap between the bags and fill fertile soil, cover the soil on each layer bags and saturate the soil with water. The other layer bags are arranged like this, total about 8 layers (based on the condition of the mushroom house). In addition, line the bags beside the two walls respectively; close to the wall and cover soil each layer. So there are 4 line bags totally forming 3 bag walls after casing soil. Two walkways with wide of about 70 cm are remained, and the fruit body will occur on both side of the walkway. Cover 4cm soil on the topside layer bags and make a gutter on it. Ventilation holes should be remained when arranging the bags beside the wall. After building up the bag wall, keep the moisture, and ventilate every day according to the situation of the mushroom house. When button appears, begin the fruiting management.

Management of premordium phase: About 15 days after casing, the mycelia grow into the soil, and interlace with the mycelia of the other bags around, forming 3 mycelia walls. At the time, the mushroom house should be kept the temperature of 12-14°C, the relative humidity of 85-90%, the scatter light of 150-200 Lux, the air fresh and the CO2concentration less than 0.1%. About 7 days later, the thickly dotted white premordium with rice size appear on the substrate surface. The premordium elongate to form the shape of needlepoint. Another 5 days later, the needlepoint button develops into puce globose small cap. At the moment roll up the bag and disclose the button, and perform the fruiting management.

Management of forming phase: With the fruit body development, enhance the ventilation; supplement the water twice every day to raise the air humidity around the fruit body. After the first flush mushroom is harvested, add water to the gutter on the mycelia wall in time to meet the requirement of next flush mushroom. Supplementing water to the mycelia wall is a measure for high production. It keeps the moisture of the substrate, increases the enzyme activity to make the substrate be utilized sufficiently and satisfy the nutrition requirement for mushroom growth. Under suitable condition, the mushroom grow orderly and rapidly from the mycelia wall with tender context, high production and good quality. The biological efficiency may approach 150%.

IV. Harvesting and grading

Harvesting in proper time and grading carefully is an important step for improving the market value of Hypsizygus marmoreus. When the cap diameter reach 1.5-4 cm, the mushroom should be harvested in time. When harvesting, press the substrate around the root with one hand, hold the stipe with the other hand, and wrest down the whole cluster of mushroom slightly. When finish the first flush mushroom harvest, clean the remaining stipes, pieces and dead mushroom on the substrate surface, and supplement water. About 15 days later the second flush button will occur, perform the management as before. Four flush, sometimes five flush mushroom can be harvested.

In general, the mushroom can be divided into 3 grades. The first flash mushroom has a cap diameter of 1.5-2.5 cm and stipe length less than 4 cm; the second flash mushroom has a cap diameter of 2.6-3.5 cm and stipe length less than 4 cm; and the third flash mushroom has a cap diameter of 3.6-4.5 cm and stipe length less than 4 cm.